Electrical junction boxes used in telecommunications provide an organized and convenient interface for connecting communication equipment in a building, such as telephones, facsimile machines and computer modems, with the regional lines of a telephone system. One example of such a junction box is the "building entry protection" unit or BEP.
Traditionally, BEPs are constructed having three interconnected parts called "fields". A first field has a multiplicity of wire connectors for attaching the telephone wiring within the building (the inside lines) to the BEP.
The wire connectors are, in turn, electrically connected to the second field which houses a multiplicity of replaceable surge protectors. Each inside telephone line is connected to an outside telephone line through an individual surge protector. The surge protector functions to ground and thereby isolate the outside telephone line from the inside telephone line in the event of a power surge in the outside line, such as that produced by a lightning strike or an accidental contact of a power line with the telephone cable. Such a current, if allowed to travel beyond the BEP, could destroy the communication equipment within the building and possibly electrocute a person using the equipment at the time of the surge.
The surge protectors shunt the dangerous current surge to ground and thereby protect the users and equipment. The surge protectors are electrically connected to the outside telephone lines in the third field of the BEP called the splice chamber. The outside lines, bundled as a cable, enter the BEP via the splice chamber where individual lines from the cable are spliced with wire segments which lead to the surge protectors. Usually, the wire segments in the splice chamber are thinner gauge than both the outside and inside wires of the system and, therefore, the most likely point to catch fire due to a power surge. In this manner, any fire that occurs will likely be confined to the splice chamber. To prevent the spread of fire from the BEP itself, the splice chamber is fully enclosed, having an access door to permit servicing of the wires in the splice chamber.
The three fields of the BEP are typically arranged side-by-side in an enclosure which is mounted to a wall of the building. This BEP configuration is inefficient, however, because it requires a relatively large enclosure to handle a relatively modest number of telephone lines. Such BEPs were adequate in the past when fewer telephone lines were required, for example, in office buildings. However, with the proliferation of telephones, facsimile machines and computer modems in modern offices, the demand for telephone lines has increased to the point where greater space efficiency is required.
It is an object of the invention to provide a compact electrical junction box for efficiently effecting a multiplicity of wire connections.
It is another object of the invention to provide a junction box in which the wire connections are readily serviceable.
It is yet another object of the invention to provide a junction box which will hinder the spread of fire in the event of a current surge.
It is still another object of the invention to provide a junction box which can provide a safe path to ground for a current surge.
These and other objects will become apparent from a consideration of the following drawings and detailed description of the invention.